nologin: User isn't actually allowed to log in even if the password matches, with optionally a different reason given as the authentication failure message.

nodelay: Don't delay reply to client in case of an authentication failure.

nopassword: If you want to allow all passwords, use an empty password and this field.

fail: If set, explicitly fails the passdb lookup. (v2.2.22+)

k5principals: if using "auth_mechanisms = gssapi", may contain Kerberos v5 principals allowed to map to the current user, bypassing the internal call to krb5_kuserok(). The database must support credentials lookup. (v2.2+)

delay_until=<UNIX timestamp>[+<max random secs>]: Delay login until this time. The timestamp must be less than 5 minutes into future or the login will fail with internal error. The extra random seconds can be used to avoid a load spike of everybody getting logged in at exactly the same time. (v2.2.25+)

noauthenticate: Do not perform any authentication, just store extra fields if user is found. (v2.2.26+/v2.3)

How to return these extra fields depends on the password database you use. See the password database pages on how to do it. Some passdbs however don't support returning them at all, such as PAM.

The password database may also return fields prefixed with userdb_. These fields are only saved and used later as if they came from the user database's extra fields. Typically this is done only when using prefetch userdb.

Note that boolean fields are true always if the field exists. So nodelay, nodelay=yes, nodelay=no and nodelay=0 all mean that the nodelay field is true. With SQL the field is considered to be non-existent if its value is NULL.

LDAP

Note about the "proxy", "proxy_maybe" and any other boolean type fields: these represent an existence test. Currently this translates to "will proxy (or proxy_maybe) if this attribute exists". This allows the proxy behaviour to be selectable per user. To have it "always" on, use a template, e.g.: